Today, vehicles have communication services that allow information to be exchanged between vehicles themselves or between vehicles and infrastructure units. By way of example, infrastructure units are traffic lights or other communication units that transmit information about a traffic light phase or information about a building that is worth seeing or about free parking spaces. Other examples of information that can be sent by an infrastructure unit or a vehicle are an accident report, a vehicle with blue lights activated, a fast vehicle approaching a junction, etc.
In the prior art, the document WO 2006072850 A1 describes an apparatus and method for forwarding warning messages between vehicles in particular hazard situations.
The document DE 10 2009 054 795 A1 is known from the prior art. It describes a mobile communication module in a vehicle that can send vehicle-to-X messages to neighboring vehicles and is additionally capable of communicating with a control unit installed in the vehicle in order thereby to interchange data for the messages with the control unit.
The document DE 10 2011 010 846 A1 describes a method for line-of-sight-independent data transmission from a transmitter to a receiver in a car-to-car or car-to-infrastructure communication system.
The document DE 10 2008 052 382 A1 describes a method for forwarding messages in a space that is restricted for the purposes of radio, particularly in the case of what is known as car-to-X communication. This involves messages being forwarded by stations, the stations being both the transmitters and receivers of messages. It involves each receiving station that is located within a range of a sending station automatically ascertaining a respective position within the range of the sending station from a signal strength of the received messages. The received messages are then intended to be forwarded only by that receiving station that establishes that it is located at the edge of the range of the sending station. This station located at the edge of the range of the sending station is the best candidate for forwarding a message quickly and reliably, with congestion on a radio channel additionally being avoided and resources saved.